This product is suitable for retrofit folding bikes, city bikes, and electric bikes. Lightweight with high axial strength and wide compatibility. Standard precision machining ensures chain retention, increases service life, and reduces friction. A reliable replacement option for bike repair and upgrade, compatible with various bike models. Features a 170mm crank arm length with no overlap between crank arm and chainring. Specifications: 48T BCD double chainring x 170mm crank arm with square taper bottom bracket, includes 9/16-inch pedal axle, and chain cover. Compatible with 6-speed and 7-speed drivetrains. Recommended for use with standard bicycle crank configurations. Color: Black Material: Aluminum alloy Package Contents: 1 x Crank Set Note: The package includes only the items listed above. Other accessories are not included. Due to lighting and display differences, the actual color may vary slightly from the image. Measurement tolerance is +/- 1-3 cm.